The aim of this meta-analysis of randomized controlled trials is to evaluate the clinical outcome of intraoperative application of autologous platelet rich plasma (PRP) in total knee arthroplasty.

The electronic databases of PubMed, Web of Science, Cochrane Library, Excerpta Medica Database (Embase), China Biology Medicine (CBM) disc, China National Knowledge Infrastructure (CNKI), WANFANG Database and China Science and Technology Journal Database(VIP) were searched from inception to September, 2020. All the randomized controlled trials involving efficacy of clinical outcome of application of PRP in total knee arthroplasty were selected. The literature was screened according to the criteria of only randomized controlled clinical trials (RCTs) but not review, non-randomized trials and animal experiments. Data of estimated blood loss, knee joint range of motion (ROM), hospital stay duration and complications were assessed with meta analysis by RevMan 5.3 software.

Seven RCTs were enrolled. The estimated total blood loss of the PRP group was less than that of the control group [mean difference (MD)=-132.32, 95% confidence interval (CI) (-231.24, -33.40), P=0.009]. The length of hospital stay in the PRP group was shorter than that in the control group [MD=-2.12, 95% CI (-3.47, -0.76), P=0.002]. The incidence of postoperative complications in the PRP group was lower than that in the control group [odds ratio (OR)=0.45, 95% CI (0.22, 0.91), P=0.03]. ROM in the PRP group was not greater than that in the control group [two days after operation: MD =0.80, 95% CI(-2.87, 4.46), P =0.67; three days after operation: MD =1.23, 95% CI (-4.12, 6.58), P =0.65; five days after operation: [MD =2.93, 95% CI(-0.60, 6.46), P =0.10; seven days after operation: MD =2.09, 95% CI(-4.63, 8.82), P =0.54; two weeks after operation: MD =-0.88, 95% CI(-3.70, 1.94), P =0.54; six weeks after operation: MD =3.93, 95% CI(-5.17, 13.02), P =0.40; three months after operation: MD =1.00, 95% CI(-4.15, 6.15), P =0.70].

PRP application in TKA would significantly reduce total blood loss, length of hospital stay and surgical complications, while the knee joint ROM may not improve.